SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '16218ffa3b68b255515ebf2b629b72cde180d2d6d4e85df9ccd13d6bafd80b38' 
  AND token = 'LrJuI15bGYZK+3Dnn39q1D/vFCuYoLeotyPTor34oa0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}